Thermosetting composition, and method for manufacturing thermoset resin

ABSTRACT

A thermosetting composition comprising: (A) a (meth)acrylate compound having a viscosity at 25° C. of 1 to 300 mPa·s with which a substituted or unsubstituted aliphatic hydrocarbon group including 6 or more carbon atoms is ester-bonded; (B) spherical silica; and (C) a white pigment, and having a shear viscosity at 25° C. and 10 s −1  of 1 Pa·s or more and 500 Pa·s or less and a shear velocity at 25° C. and 100 s −1  of 0.3 Pa·s or more and 100 Pa·s or less.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/321,517, filed Dec. 22, 2016, which is a national stage ofPCT/JP2015/003111, filed Jun. 22, 2015, which claims priority toJapanese application number 2014-128158, tiled Jun. 23, 2014. Thebenefit of priority is claimed to each of the foregoing, and the entirecontents of each of the foregoing are incorporated herein by reference.

TECHNICAL FIELD

The invention relates to a thermosetting composition and a method forproducing a thermoset resin.

BASCKGROUND ART

A light-emitting device utilizing a light-emitting semiconductor such aslight-emitting diode (LED) that has been widespread in recent years isnormally produced by a method in which a light-emitting semiconductor(LED) is fixed on a lead frame of a molded product obtained byintegrally molding a synthetic resin as a reflector in the shape of aconcave on a lead frame, followed by sealing with a sealant such as anepoxy resin or a silicone resin.

As the material for a reflector, Patent Document 1 discloses acomposition that provides a cured product excellent in heat resistanceand weatherability, as well as in adhesiveness with peripheralcomponents, which is obtained by mixing a thermoset resin such as anacrylate resin with a white pigment such as titanium oxide.

When titanium oxide as a representative white pigment is used, theviscosity of a thermosetting composition tends to increase, and thefluidity of the thermoset resin liquid is deteriorated. If the fluidityof the liquid is poor, when a resin molded product is formed in a leadframe, bending or un-filling of a reflector, formation of voids or burrsin a lead frame molded body occur, and hence mass producibility of alight-emitting device becomes insufficient. Further, it is required thatonly a slight effect be exerted on continuous moldability if athermosetting composition is stored at normal temperature.

RELATED ART DOCUMENTS Patent Document

Patent Document 1: WO2012/056972

SUMMARY OF THE INVENTION

An object of the invention is to provide a thermosetting compositionthat is excellent in continuous moldability, i.e. can preventun-filling, generation of voids and formation of burrs in the resultingmolded product when molding a reflector in a lead frame.

Another object of the invention is to provide a method for molding athermosetting composition and a method for producing a thermoset resinthat is excellent in continuous moldability, i.e. can preventun-filling, generation of voids, and formation of burrs in the resultingmolded product when molding a reflector in a lead frame.

According to the invention, the following thermosetting composition orthe like can be provided.

1. A thermosetting composition comprising the following components (A)to (C), which has a shear viscosity at 25° C. and 10 s⁻¹ of 1 Pa·s ormore and 500 Pa·s or less and a shear viscosity at 25° C. and 100 s⁻¹ of0.3 Pa·s or more and 100 Pa·s or less:

(A) a meth(acrylate) compound having a viscosity at 25° C. of 1 to 300mPa·s with which a substituted or unsubstituted alicyclic hydrocarbongroup including 6 or more carbon atoms is ester-bonded;

(B) spherical silica; and

(C) a white pigment.

2. The thermosetting composition according to 1, wherein the content ofcomponent (B) is 10 to 90 mass % and the content of component (C) is 3to 50 mass % relative to 100 mass % of the total of the components (A)to (C).

3. The thermosetting composition according to 1 or 2, wherein the(meth)acrylate compound is a (meth)acrylate compound with which one ormore aliphatic hydrocarbon groups selected from a substituted orunsubstituted adamantyl group, a substituted or unsubstituted norbornylgroup, a substituted or unsubstituted isobornyl group and a substitutedor unsubstituted dicyclopentanyl group is ester-bonded.4. The thermosetting composition according to any one of 1 to 3, whichfurther comprises one or more components selected from the followingcomponents (D) to (F), wherein the content of the component (C) is 3 to50 mass % and the content of the component (B) is 10 to 90 mass %relative to 100 mass % of the total of the components (A) to (F):

(D) (meth)acrylic acid or a monofunctional (meth)acrylate compoundhaving a polar group;

(E) a monofunctional (meth)acrylate compound other than the components(A) and (D); and

(F) one or more compounds selected from the group consisting ofpolyfunctional (meth)acrylate compounds other than the component (A).

5. The thermosetting composition according to any one of 1 to 4, whereinthe spherical silica is subjected to a (meth)acrylsilane surfacetreatment.

6. The thermosetting composition according to any one of 1 to 5, whereinthe average pa size of primary particles of the spherical silica is 0.1to 100 μm.

7. The thermosetting composition according to any one of 1 to 6, whichfurther comprises one or more components selected from the followingcomponents (G) and (H):

(G) a plate-like filler; and

(H) nano particles.

8. A method for producing a thermoset resin comprising the steps of:

supplying the thermosetting composition according to any one of 1 to 7to a plunger;

filling by means of the plunger the thermosetting composition that isfilled in the plunger in the cavity of a mold;

heat curing the thermosetting composition in the cavity; and

taking out the thermoset resin that is cured.

9. The method for producing a thermoset resin according to 8, whereinthe temperature of the mold in the cavity part is 100° C. or higher and180° C. or lower.

10. The method for producing a thermoset resin according to 8 or 9,wherein, during the step of filling by means of the plunger thethermosetting composition that is filled in the plunger in the cavity ofthe mold, the thermosetting composition is filled in the cavity of themold through a flow channel of which the temperature is controlled to be50° C. or lower.11. The method for producing a thermoset resin according to any one of 8to 10, wherein, during the step of filling by means of the plunger thethermosetting composition that is filled in the plunger in the cavity ofthe mold, a gate system is provided in a flow channel between theplunger and the cavity for shutting off the flow of the thermosettingcomposition and the transfer of heat.12. The method for producing a thermoset resin according to 11, whereinthe gate of the gate system is opened, the thermosetting composition isfilled in the cavity of the mold, and as for the heat curing, theinjection pressure of the thermosetting composition is increased afterthe start of the curing, pressure holding starts before the completionof the curing, and after the completion of the pressure holding, thegate of the gate system is closed to complete the heat curing.13. The method for producing a thermoset resin according to any one of 8to 12, wherein the filling step and the heat curing step are conductedwithin 0.2 to 3 minutes.

ADVANTAGEOUS EFFECTS OF THE INVENTION

According to the invention, it is possible to provide a thermosettingcomposition that is excellent in continuous moldability, i.e. canprevent un-filling, generation of voids, and formation of burrs in theresulting molded product when molding a reflector in a lead frame.

According to the invention, it is possible to provide a method formolding a thermosetting composition and a method for producing athermoset that is excellent in continuous moldability, i.e. can preventun-filling, generation of voids, and formation of burrs in the resultingmolded product when molding a reflector in a read frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of a filling apparatus thatcan be used in the method for producing a thermoset resin of theinvention;

FIG. 2 is a schematic cross-sectional view of a mold of a moldingmachine that can be used in the method for producing a thermosettingcomposition of the invention;

FIG. 3 is a view showing the relationship between the viscosity and timeaccording to one embodiment of the method for producing a thermosetresin of the present invention;

FIG. 4 is a schematic cross-sectional view showing one embodiment of asubstrate for mounting an optical semiconductor device, which isconstituted by using the thermosetting composition of the invention andan optical semiconductor light-emitting device of the invention, inwhich (a) is a cross-sectional view of a lead frame, (b) is across-sectional view of a substrate for mounting an opticalsemiconductor device and (c) is a cross-sectional view of an opticalsemiconductor light-emitting device; and

FIG. 5 is a schematic cross-sectional view showing another embodiment ofthe substrate for mounting an optical semiconductor device constitutedby using the thermosetting composition of the invention and the opticalsemiconductor device, in which (a) is a cross-sectional view of a leadframe, (b) is a cross-sectional view of a substrate for mounting anoptical semiconductor device and (c) is a cross-sectional view of anoptical semiconductor light-emitting device.

MODE FOR CARRYING OUT THE INVENTION

[Thermosetting Composition]

The thermosetting composition of the invention comprises the followingcomponents (A) to (C) and has a shear viscosity at 25° C. and 10 s⁻¹ of1 Pa·s or more and 500 Pa·s or less, and a shear viscosity at 25° C. and100 s⁻¹ of 0.3 Pa·s or more and 100 Pa·s or less.

(A) (meth)acrylate compound having a viscosity at 25° C. of 1 to 300mPa·s with which a substituted or unsubstituted alicyclic hydrocarbongroup is ester-bonded

(B) spherical silica

(C) a white pigment.

As for the thermosetting composition of the invention (hereinafter,often simply referred to as the “composition of the invention”), byallowing the composition comprising the above-mentioned components (A)to (C) to have a shear viscosity at 25° C. and 10 s⁻¹ of 1 Pa·s or moreand 500 Pa·s or less and to have a shear viscosity at 25° C. and 100 s⁻¹of 0.3 Pa·s or more and 100 Pa·s or less, it is possible to allow thecomposition to be improved in continuous moldability, as well as tosuppress generation of burrs in the molded product. Further, it canexhibit excellent storageability at normal temperature.

If each shear viscosity is not satisfied and low, a large amount ofburrs is formed, and deburring may become necessary, and is notpreferable since it deteriorates the appearance of the product. On theother hand, a high shear viscosity is also unfavorable, since un-fillingof a molded product occurs in a molded product to cause appearance of aproduct to be deteriorated.

The shear viscosity at 100 s⁻¹ and the shear viscosity at 10 s⁻¹respectively correspond to the first half and the second half of thepouring of the raw material in a cavity. If each value is low, burrs areformed at each state. If the shear viscosity is high, un-filling occursin each state. Therefore, the viscosities at the both shear velocitiesare adjusted to be within the above-mentioned range.

The viscosity of the composition can be in the above-mentioned range byappropriately adjusting the amount of each component in the composition.The shear viscosity of the composition can be confirmed by aviscoelastic measurement apparatus.

Hereinbelow, an explanation will be made on each of the componentscontained in the composition of the invention:

[Component (A): (Meth)acrylate compound having a viscosity at 25° C. of1 to 300 Pa·m with which a substituted or unsubstituted alicyclichydrocarbon group including 6 or more carbon atoms is ester-bonded]

The composition of the invention comprises, as the component (A), a(meth)acrylate compound having a viscosity at 25° C. of 1 to 300 Pa·mwith which a substituted or unsubstituted alicyclic hydrocarbon groupincluding 6 or more carbon atoms is ester-bonded (hereinafter oftenreferred to as compound (A)).

Since compound (A) provides a polymer having a high glass transitiontemperature, by incorporating it in the composition, when thecomposition is used as a raw material of a reflector of an opticalsemiconductor, it is possible to improve heat resistance and lightresistance.

The number of carbon atoms of the alicyclic hydrocarbon group of thecompound (A) is 6 or more, preferably 6 to 30, with 7 to 15 being morepreferable.

The alicyclic hydrocarbon group including 6 or more carbon atoms mayhave a substituent. As the substituted or unsubstituted alicyclichydrocarbon group including 6 or more carbon atoms, a substituted orunsubstituted adamantyl group, a substituted or unsubstituted norbomylgroup, a substituted or unsubstituted isobornyl group, a substituted orunsubstituted dicyclopentanyl group and a substituted or unsubstitutedcyclohexyl group can be given, for example.

The compound (A) is preferably a (meth)acrylate compound (I) having anadamantyl group represented by the following general formula, a(meth)acrylate compound (II) having an isobornyl group, a (meth)acrylatecompound (III) having a norbornyl group and a (meth)acrylate compound(IV) having a dicyclopentanyl group.

In the formulas (I), (II), (III) and (IV), R¹s independently represent ahydrogen atom or a methyl group.

Xs independently represent a single bond, an alkylene group including 1to 4 carbon atoms or an oxyalkylene group including 1 to 4 carbon atoms.

As the alkylene group including 1 to 4 carbon atoms, a methylene group,an ethylene group, a trimethylene group, a propylene group, atetramethylene group, a butylene group, a 2-methyltrimethylene group orthe like can be given.

As the oxyalkylene group including 1 to 4 carbon atoms, an oxymethylenegroup, an oxyethylene group, an oxypropylene group, an oxybutylene groupor the like can be given. Among these Xs, a single bond is preferable inrespect of heat resistance.

U is a hydrogen atom, an alkyl group including 1 to 4 carbon atoms, ahalogen atom, hydroxide group or ═O in which two Us are bonded to eachother, k is an integer of 1 to 15. I is an integer of 1 to 8, m is aninteger of 1 to 11. n is an integer of 1 to 15.

When plural Us are present in the formula, the plural Us may be the sameas or different from each other.

The compound (A) is further preferably adamantyl methacrylate,1-norbonyl methacrylate, 1-isobornyl methacrylate or 1-dicyclopentanylmethacrylate, more preferably 1-adamantyl methacrylate, 1-norbornylmethacrylate and 1-isobornyl methacrylate. These compounds have aviscosity at 25° C. of 1 to 300 mPa·s.

The (meth)acrylate compound with which a substituted or unsubstitutedalicyclic hydrocarbon group including 6 or more carbon atoms isester-bonded may be used singly or in combination of two or more.

The viscosity of the compound (A) is 1 to 300 mPa·s, more preferably 1to 200 mPa·s, with 1 to 100 mPa·s being further preferable. Byincorporating the compound (A) having such a low viscosity into thecomposition, it is possible to increase the filling property ofspherical silica and a white pigment.

The viscosity of the compound (A) can be measured by a rheometer or arotary viscometer, for example.

[Component (B): Spherical Silica]

As the component (B), the composition contains spherical silica (SiO₂).

The white pigment (C) such as barium titanate mentioned later tends tobe precipitated in a liquid, and hence, the usable amount thereof islimited. By using spherical silica in combination with the whitepigment, the content of an inorganic substance in the composition can befurther increased, whereby material strength, reflectance, heatresistance and light resistance can be further improved.

Further, it is possible to keep the fluidity of the composition, wherebythe filling property at the time of molding can be improved.

The average diameter of primary particles of spherical silica is 0.1 to100 μm, for example, by measurement by laser diffraction. The averagediameter of primary particles of spherical silica is preferably 0.5 to70 μm, with 1 to 50 μm being more preferable, With this particlediameter, the filling property of the spherical silica can be improvedor blockage of the molding channel can be suppressed.

It is preferred that the spherical silica be subjected to a surfacetreatment (acrylsilane treatment, in particular).

By organically modifying the spherical silica by reacting a hydroxylgroup of the surface of the spherical silica with a silane couplingagent (in particular, an acrylic silane coupling agent), the wettabilityof the spherical silica can be improved, and as a result, dispersibilityof the spherical silica in organic components (component (A) andarbitrary components (D), (E) and (F)) can be improved, and the strengthof a cured product can be improved.

The content of the spherical silica in the composition is, relative to100 mass % of the total of the components (A), (B) and (C), or relativeto 100 mass % of the total of the components (A) to (H) if one or moreof arbitrary components (D), (E), (F), (G) and (H) mentioned later arepresent, 10 to 90 mass %, for example, preferably 20 to 85 mass %, morepreferably 30 to 80 mass %, with 35 to 80 mass % being furtherpreferable.

If the content of the spherical silica in the composition is less than10 mass % relative to the above-mentioned total mass %, the viscosity ofthe composition is lowered, and as a result, burrs may be generated andstorability at normal temperature may be deteriorated. As for thephysical properties, the material strength may be insufficient. If thecontent of the spherical silica is larger than 90 mass %, the viscositymay be increased to deteriorate fluidity.

[Component (C): White Pigment]

The composition of the invention comprises a white pigment as thecomponent (C).

As for specific examples of the white pigment, barium titanate,zirconium oxide, zinc oxide, boron nitride, titanium dioxide, alumina,zinc sulfide, magnesium oxide, potassium titanate, barium sulfate,calcium carbonate, silicone particles or the like can be given. Amongthese, in respect of high reflectance and easiness in availability,barium titanate, zirconium oxide, zinc oxide, boron nitride and titaniumdioxide are preferable. In respect of a higher reflectance, titaniumdioxide is preferable. A white pigment can be used singly or incombination of two or more.

As for the crystal type of titanium dioxide, rutile type titaniumdioxide and anatase type titanium dioxide are present. Anatase typetitanium dioxide may deteriorate the resin due to its light catalystfunction. Therefore, in the invention, it is preferable to use rutiletype titanium dioxide.

In respect of dispersibility of a white pigment in the composition, thevolume average particle diameter of a white pigment is preferably 0.01to 20 μm, more preferably 0.05 to 10 μm, and further more preferably 0.1to 1 μm. The volume average particle size can be obtained as D50 in theparticle size distribution measurement by the laser type lightdiffraction method.

A white pigment may be hollow particles. If a white pigment is hollowparticles, visible rays that pass the outer shell of hollow particlesare reflected in the hollow part. Therefore, in order to increase thereflectance in the hollow part, it is preferred that difference inrefractive index between a part that constitutes the hollow particlesand a gas that is present within the hollow particle be large. The gasthat is present in the hollow particles is normally air, but it may bean inert gas such as nitrogen and argon. Further, the inside of thehollow particles may be vacuum.

A white pigment may be subjected to an appropriate surface treatmentwith a silicon compound, an aluminum compound, an organic substance orthe like. As the surface treatment, a (meth)acrylsilane treatment, analkylation treatment, a trimethylsilylation treatment, a siliconetreatment, a treatment with a coupling agent or the like can be given.

The content of the white pigment in the composition is, relative to 100mass % of the total of components (A), (B) and (C), or relative to 100mass % of the total of components (A) to (H), if one or more of thearbitrary components (D), (E), (F), (G) and (H) are present, 3 to 50mass %, for example, preferably 4 to 40 mass %, more preferably 5 to 35mass %, and further preferably 5 to 25 mass %.

If the content of the white pigment in the composition is less than 3mass % relative to the total mass % mentioned above, the degree ofwhiteness may be deteriorated. If the content of the white pigment islarger than 50 mass %, the viscosity becomes too high, resulting indeteriorated fluidity.

The composition of the invention may comprise other polymerizableacrylate compounds than the compound (A) as an arbitrary component. Asthe arbitrary component, one or more selected from the followingcomponents (D), (E) and (F) can be given.

Component (D): (Meth)acrylic acid or a monofunctional (meth)acrylatecompound having a polar group

Component (E): Monofunctional (meth)acrylate compound other thancomponents (A) and (D)

Component (F): Polyfunctional (meth)acrylate compound other thancomponent (A)

Hereinafter, the component (D), the component (E) and the component (F)may often be referred to as compound (D), compound (E) and compound (F),respectively.

The total content of the compounds (A), (D), (E) and (F) in thecomposition of the invention is preferably 1 to 40 mass %, morepreferably 5 to 30 mass %, and further preferably 10 to 20 mass %,relative to 100 mass % of the total of components (A) to (F) or relativeto 100 mass % of the total of components (A) to (G).

The content of the compound (A) in the composition of the invention is,if components (D), (E) and (F) are present, preferably 10 to 70 mass %,more preferably 15 to 60 mass %, and further preferably 20 to 50 mass %,relative to 100 mass % of the total of the compounds (A), (D), (E) and(F).

[Component (D): (Meth)acrylic Acid or Monofunctional (meth)acrylateCompound Having a Polar Group]

The compound (D) is (meth)acrylic acid or a monofunctional(meth)acrylate compound having a functional group. It is not a compoundwith which an alicyclic hydrocarbon group including 6 or more carbonatoms is bonded, and hence, is not overlapped with the compound (A).

Since the compound (D) has polarity, by incorporation thereof into thecomposition, it forms a hydrogen bond or the like with a metal surfaceor the like having polarity, thereby to improve the adhesiveness of thecomposition. Further, due to the presence of a polar group, wettabilityis improved. Meanwhile, while an alkylene glycol group may affectbestowment of adhesiveness, alkylene glycol (meth)acrylate is notincluded in the compound (D).

As the monofunctional (meth)acrylate compound having a polar group, a(meth)acrylate compound with which a substituent including an atom otherthan carbon and hydrogen is ester-bonded can be given. As thesubstituent, a hydroxyl group, an epoxy group, a glycidyl ether group, atetrahydrofurfuryl group, an isocyanate group, a carboxyl group, analkoxysilyl group, a phosphoric acid ester group, a lactone group, anoxetane group, a tetrahydropyranyl group, an amino group or the like canbe given.

As specific examples of the monofunctional (meth)acrylate compoundhaving a polar group, 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate,4-hydroxybutyl(meth)acrylate (e.g., product name: 4-HBA, manufactured byNippon Kasei Chemical Co., Ltd.), cyclohexane dimethanolmono(meth)acrylates (e.g., product name: CHMMA, manufactured by NipponKasei Chemical Co., Ltd.), glycidyl (meth)acrylate, 4-hydroxybutylacrylate glycidyl ether (e.g., product name: 4-HBAGE, manufactured byNippon Kasei Chemical Co., Ltd.), tetrahydrofurfuryl (meth)acrylate,2-isocyanatoethyl(meth)acrylate, 2-(meth)acryloyloxyethyl succinate,2-(meth)acryloyloxyethyl hexahydrophthalic acid,3-(meth)acryloxypropyltrimethoxysilane,3-(meth)acryloxypropylmethyldimethoxysilane,3-(meth)acryloxypropyltriethoxysilane,3-(meth)acryloxypropylmethyldiethoxysilane,2-(meth)acryloyloxyethylphosphate,bis(2-(meth)acryloyloxyethyl)phosphate, KAYAMER PM-2, KAYAMER PM-21(product name, manufactured by Nippon Kayaku Co., Ltd.),γ-butyrolactone(meth)acrylate, (meth)acrylic acid (3-methyl-3-oxetanyl),(meth)acrylic acid (3-ethyl-3-oxetanyl),tetrahydrofurfuryl(meth)acrylate, dimethylaminoethyl (meth)acrylate,diethylaminoethyl(meth)acrylate or the like can be given.

In the invention, as the compound (D), one selected from theabove-mentioned (meth)acrylic acid and the above-mentioned(meth)acrylate compound having a polar group may be used singly or incombination of two or more.

In respect of adhesiveness, the content of the compound (D) in thecomposition of the invention is, preferably 1 to 40 mass %, morepreferably 5 to 15 mass %, and further preferably 7 to 25 mass %,relative to 100 mass % of the total of the compounds (A), (D), (E) and(F).

[Component (E): Monofunctional (meth)acrylate Compound Other Than theComponents (A) and (D)]

[Component (F): Polyfunctional (meth)acrylate Compound Other Than theComponent (A)]

The compound (E) is a monofunctional group (meth)acrylate compound otherthan the compounds (A) and (D). By incorporating the compound (E) intothe composition of the invention, viscosity or hardness of a curedproduct can be adjusted, and occurrence of cracks or the like can besuppressed.

Further, the compound (F) is a polyfunctional (meth)acrylate compoundother than the compound (A). A polyfunctional (meth)acrylate compoundother than the compounds (A), (D) and (E) may be incorporated into thecomposition within an amount range that does not inhibit theadvantageous effects of the invention in respect of mechanical strengthor curing speed.

As the (meth)acrylate compound other than the compounds (A) and (D)(compounds (E) and (F)), at least one (meth)acrylate compound selectedfrom the group consisting of (meth)acrylate-modified silicone oil,(meth)acrylate having an aliphatic hydrocarbon group, polyalkyleneglycol(meth)acrylate having a number average molecular weight of 400 ormore, urethane acrylate, epoxy acrylate and polyester acrylate can begiven. As the compound (E), among these compounds, a monofunctional(meth)acrylate compound can be selected and used. As the compound (F),among these compounds, a polyfunctional (meth)acrylate compound can beselected and used.

The (meth)acrylate-modified silicone oil that can be used in theinvention is a compound that has an acrylic group and/or a methacrylicgroup at its end, and preferably is a compound havingdialkylpolyoxysiloxane in its skeleton. In many cases, this(meth)acrylate-modified silicone oil is a modified product ofdirnethylpolysiloxane. Instead of a methyl group, all or part of thealkyl group in the dialkylpolysiloxane skeleton may be replaced with aphenyl group or an alkyl group other than a methyl group. As the alkylgroup other than a methyl group, an ethyl group, a propyl group or thelike can be given. As the commercial products of these compounds,single-end reactive silicone oil (for example, X-22-174DX, X-22-2426,X-22-2475), both-end reactive silicone oil (for example, X-22-164A,X-22-164C, X-22-164E) (these are products manufactured by Shin-EtsuChemical Co., Ltd.), methacrylate-modified silicone oil (for example,BY16-152D, BY16-152, BY16-152C) (these are products manufactured by DowCorning Toray Co., Ltd.) can be used.

As the (meth)acrylate-modified silicone oil, it is possible to usepolydialkylsiloxane having an acryloxyalkyl end or a methacryloxyalkylend. Specifically, methacryloxypropyl-ended polydimethylsiloxane,(3-acryloxy-2-hydroxypropyl)-ended polydimethylsiloxane, an ABA typetriblock copolymer composed of acryloxy-ended ethylene oxidedimethylsiloxane (A block) and ethylene oxide (B block),methacryloxypropyl-ended branched polydimethylsiloxane or the like canbe given.

The (meth)acrylate having an aliphatic hydrocarbon group that can beused in the invention is a compound in which a (meth)acrylate group isbonded with a residue obtained by removing a hydrogen atom from analiphatic hydrocarbon compound.

As the aliphatic hydrocarbon compound that can derive the (meth)acrylatehaving an aliphatic hydrocarbon group that can be used in the invention,alkane is preferable. Alkane including 12 or more carbon atoms is morepreferable in respect of physical properties of a cured product of theinvention.

In the (meth)acrylate having an aliphatic hydrocarbon group that can beused in the invention, the number of the (meth)acrylate group is notspecifically restricted, and it may be one or plural. If the number ofthe (meth)acrylate group is one, the aliphatic hydrocarbon group ispreferably an alkyl group, and more preferably a straight-chain alkylgroup including 12 or more (preferably 12 to 24, more preferably 12 to18) carbon atoms. If the number of the (meth)acrylate group is two, thealiphatic hydrocarbon group is preferably an alkylene group, and is morepreferably a straight-chain alkylene group including 12 or more(preferably 12 to 24, more preferably 12 to 18) carbon atoms.

As specific examples of the alkyl group including 12 or more carbonatoms, a dodecyl group (including lauryl group), a tridecyl group, atetradecyl group, a hexadecyl group, an octadecyl group (including astearyl group), an eicosyl group, a triacontyl group, a tetracontylgroup or the like can be given. The alkyl group or the alkylene groupincluding 12 or more carbon atoms may be an alkyl group or an alkylenegroup derived from a hydride of a polymer such as polybutadiene andpolyisoprene. As specific examples of the alkylene group including 12 ormore carbon atoms, a divalent residue obtained by removing a hydrogenatom from the above-mentioned alkyl group can be given.

As specific examples of the (meth)acrylate having an aliphatichydrocarbon group, lauryl(meth)acrylate, tridecyl(meth)acrylate,tetradecyl(meth)acrylate, hexadecyl(meth)acrylate,stearyl(meth)acrylate, eicosyl(meth)acrylate, triacontyl(meth)acrylate,tetracontyl(meth)acrylate or the like, or an acrylic or methacryliccompound having a hydrogenated polybutadiene skeleton or a hydrogenatedpolyisoprene skeleton such as hydrogenated polybutadienedi(meth)acrylate and hydrogenated polyisoprene, di(meth)acrylate.

By using polyalkylene glycol(meth)acrylate having a number averagemolecular weight of 400 or more, the composition of the invention canprovide a cured product having an excellent tenacity. In thepolyalkylene glycol(meth)acrylate having a number average molecularweight of 400 or more that can be used in the invention, the number of a(meth)acrylate group is not particularly restricted, and it may be oneor plural.

The number average molecular weight of the compound is preferably 400 to10,000, more preferably 450 to 5,000, and further preferably 500 to3,000, in respect of tenacity or adhesiveness, and compatibility withthe components (A) and (D).

As specific examples of the polyalkylene glycol(meth)acrylate having anumber average molecular weight of 400 or more, polyethylene glycoldi(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutyleneglycol di(meth)acrylate, ethoxylated trimethylolpropanetri(meth)acrylate, ethoxylated pentaerythritol tetra(methacrylate) orthe like can be given. Among these, in respect of tenacity oradhesiveness, polyethylene glycol di(meth)acrylate is preferable.

It is preferred that the urethane acrylate, the epoxy acrylate and thepolyester acrylate that can be used in the invention do not have anaromatic group in respect of light resistance. The number-averagemolecular weight thereof is preferably 100 to 100,000, more preferably500 to 80,000, and further preferably 1,000 to 50,000 in respect oftenacity or compatibility with components (A) and (D).

Other than those mentioned above, as specific examples of themonofunctional or polyfunctional (meth)acrylate compounds (compounds (E)and (F)), the followings can be given: polyethylene glycol such asdi(meth)acrylate or polypropylene glycol di(meth)acrylate having anumber average molecular weight of less than 400; ethyl(meth)acrylate,n-butyl(meth)acrylate, isobutyl(meth)acrylate, t-butyl(meth)acrylate,isoamyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,isooctyl(meth)acrylate, isodecyl(meth)acrylate,caprolactone(meth)acrylate, ethoxydiethylene glycol(meth)acrylate,methoxytriethylene glycol(meth)acrylate,2-ethylhexyldiglycol(meth)acrylate, methoxypolyethyleneglycol(meth)acrylate, methoxydipropylene glycol(meth)acrylate,polypropylene glycol mono(meth)acrylate, tetrahydrofurhyl(meth)acrylate,trifluoroethyl(meth)acrylate, ethylene glycol di(meth)acrylate,diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,tetraethylene glycol di(meth)acrylate, dipropylene glycoldi(meth)acrylate, tripropylene glycol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate,propoxylated neopentyl glycol di(meth)acrylate, 1,3-butylene glycoldi(meth)acrylate, 1,4-butanediol di(meth)acrylate,3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanedioldi(meth)acrylate, ethoxylated hexanediol di(meth)acrylate,1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate,1,12-dodecanediol dimethacrylate, 2-methyl-1,8-octanedioldi(meth)acrylate, glycerin di(meth)acrylate, tricyclodecane dimethanoldi(meth)acrylate, hydroxypivalic acid neopentyl glycol acrylic acidadduct, 2-hydroxy-3-acryloyloxy propyl(meth)acrylate, ethoxylatedhydrogenated bisphenol A di(meth)acrylate, propoxylated hydrogenatedbisphenol A di(meth)acrylate, glycerin tri(meth)acrylate, ethoxylatedglycerin(meth)acrylate, propoxylated glycerin(meth)acrylate,trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropanetri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate,pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate,ditrimethylolpropane tetra(meth)acrylate, ethoxylated pentaerythritoltetra(meth)acrylate, dipentaerythritol penta(meth)acrylate,dipentaerythritol hexa(meth)acrylate, ethoxylated isocyanuric acidtri(meth)acrylate, ε-caprolactone-modified tris(2-acryloxyethyl)isocyanurate or the like.

In the invention, as the compound (E), among the above-mentionedmonofunctional (meth)acrylate compounds, it is possible to use onesingly or two or more in combination,

The content of the compound (E) in the composition of the invention ispreferably 10 to 80 mass %, more preferably 15 to 60 mass %, and furtherpreferably 15 to 50 mass % relative to 100 mass % of the total ofcompounds (A), (D), (E) and (F) in respect of tenacity or adhesiveness,

In the invention, as the compound (F), among the polyfunctional(meth)acrylate compounds other than the above-mentioned component (A),it is possible to use one singly or two or more in combination.

The content of the compound (F) in the composition of the invention ispreferably 5 to 60 mass %, more preferably 10 to 45 mass %, and furtherpreferably 15 to 40 mass % relative to 100 mass % of the total of thecompounds (A), (D), (E) and (F) in order not to inhibit the advantageouseffects of the invention.

It is preferred that the composition of the invention comprise one ormore selected from the following components (G) and (H),

(G) A plate-like filler

(H) Nano particles

[Component (G): Plate-Like filler]

By incorporating a plate-like filler as the component (G), the viscosityof the composition or the hardness of the resulting cured product can beadjusted, and generation of burrs at the time of molding the compositioncan be suppressed.

As specific examples of the plate-like filler, talc, kaolin, mica, clay,sericite, glass flakes, synthetic hydrotalcite, various metal foils,graphite, molybdenum disulfide, tungsten disulfide, boron nitride,plate-like iron oxide, plate-like calcium carbonate, plate-like aluminumhydroxide or the like can be given. Among them, talc, kaolin, mica,clay, graphite and glass flakes are preferable. Talc is lore preferablesince lowering in reflectance by mixing thereof is not observed

The plate-like fillers may be used singly or in combination of two ormore.

The content of the component (G) in the composition is 1 to 30 mass %,for example, preferably 3 to 20 mass %, more preferably 5 to 15 mass %,relative to 100 mass % of the total of components (A) to (H).

By incorporating nano particles as the component (H), the viscosity ofthe composition can be adjusted, and the storage stability of thecomposition at normal temperature can be kept, whereby troubles at thetime of molding can be reduced.

As the nano particles, silver, gold, silicon, silicon carbide, silica,copper oxide, iron oxide, cobalt oxide, titanium carbide, cerium oxide,ITO, ATO, hydroxyl apatite, graphene/graphene oxide, monolayer carbonnanotube, multi-layer carbon nanotube, fullerene, diamond, mesoporouscarbon or the like can be given. Silicon carbide, silica and titaniumcarbide are preferable. In respect of keeping the degree of whiteness,silica and titanium carbide are more preferable.

The nano particles can be used singly or in combination of two or more.

The content of the component (H) in the composition is 0.05 to 10 mass%, for example, preferably 0.07 to 7 mass %, and more preferably 0.1 to5 mass % relative to 100 mass % of the total of the components (A) to(H). If the content of the component (H) is 0.05 mass % or less, thestability at the time of storing at normal temperature is poor, andsolid components may be precipitated. If the content of the component(H) is 10 mass % or more, the appearance of the molded product(transferability) may be deteriorated.

The components (A), (D), (E) and (F) of the thermosetting composition ofthe invention lower the viscosity of the thermosetting composition andthe components (B), (C), (G) and (H) of the thermosetting composition ofthe invention increase the viscosity of the thermosetting composition.

In respect of allowing the shear viscosity at 25° C. and 10 s⁻¹ of thethermosetting composition to be 1 Pa·s or more and 500 Pa·s or less anda shear viscosity at 25° C. and 100 s⁻¹ of 0.3 Pa·s or more and 100 Pa·sor less, the content of the components (A), (D), (E) and (F) of thethermosetting composition is 7 to 50 mass %, preferably 7 to 35 mass %and more preferably 8 to 25 mass %, relative to 100 mass % of the totalcontent of components (A) to (H), and the content of the components (B),(C), (G) and (H) of the thermosetting composition is 50 to 93 mass %,more preferably 60 to 93 mass % and further preferably 75 to 92 mass %,relative to 100 mass % of the total content of the components (A) to(H).

By adjusting the viscosity of the thermosetting composition to be in theabove-mentioned viscosity range, it is possible to obtain a moldedproduct improved in continuous moldability, as well as to suppressformation of burrs in the resulting molded product.

The thermosetting composition of the invention comprises the components(A), (B) and (C), and further may optionally comprise at least oneselected from the components (D), (E), (F), (G) and (H).

In the thermosetting composition of the invention, the total content ofthe components (A) to (H) may be 85 wt % or more, 95 wt % or more or 99wt % or more, for example. The thermosetting composition may consistonly of the components (A) to (H).

[Additive]

The thermosetting composition of the invention may comprise, in additionto the above-mentioned components (A) to (H), polymerization initiators,antioxidants, light stabilizers, ultraviolet absorbers, plasticizers,inorganic fillers, colorants, antistatic agents, lubricants, moldrelease agents, flame retardants, leveling agent, de-foaming agents orthe like within a range that does not inhibit advantageous effects ofthe invention. As for these additives, known additives can be used.

Hereinafter, an explanation will be made on additives that can be usedpreferably in the composition of the invention.

(Polymerization Initiator)

By polymerizing the composition of the invention with heat, a curedproduct can be obtained.

In order to accelerate the polymerization reaction, a polymerizationinitiator may be contained in the composition. No specific restrictionsare imposed on the kind of a polymerization initiator. However, aradical polymerization initiator can be given, for example.

No specific restrictions are imposed on the kind of a radicalpolymerization initiator. Ketone peroxides, hydroperoxides,diacylperoxides, dialkylperoxides, peroxyketals, alkyl peresters (peroxyesters), peroxycarbonates or the like can be given.

As specific examples of ketone peroxide, methyl ethyl ketone peroxide,methyl isobutyl ketone peroxide, acetyl acetone peroxide, cyclohexanoneperoxide, methylcyclohexanone peroxide or the like can be given.

As specific examples of hydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-methanehydroperoxide, diisopropylbenzene hydroperoxide or the like can begiven.

As specific examples of diacyl peroxide, diisobutyryl peroxide,bis-3,5,5-trimethyl hexanol peroxide, dilauroyl peroxide, dibenzoylperoxide, m-toluylbenzoyl peroxide, succinic acid peroxide or the likecan be given.

As specific examples of dialkyl peroxide, dicumyl peroxide,2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,3-bis(t-butylperoxyisopropyl)hexane, t-butylcumyl peroxide, di-t-butyl peroxide, di-t-hexylperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3 or the like can begiven.

As specific examples of peroxyketal, 1,1-di-t-hexylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-hexylperoxy cyclohexane,1,1-di-t-butyl-peroxy-2-methylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di(t-butylperoxy)butane, butyl 4,4-bis-t-butylperoxypentanoic acid or the like can be given.

As specific examples of alkylperester (peroxyester),1,1,3,3-tetramethylbutylperoxy neodecanoate, α-cumylperoxy neodecanoate,t-butylperoxy neodecanoate, t-hexylperoxy neodecanoate, t-butylperoxyneoheptanoate, t-hexylperoxypivalate, t-butylperoxypivalate,1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate,t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate,t-butylperoxy isobutyrate, di-t-butylperoxy hexahydroterephthalate,tetramethylbutylperoxy-3,5,5-trimethylhexanoate, t-amylperoxy3,5,5-trimethyl hexanoate, t-butylperoxy 3,5,5-trimethyl hexanoate,t-butylperoxy acetate, t-butylperoxy benzoate, di-butylperoxytrimethyladipate, 2,5-dimethyl-2,5-di-2-ethylhexanoylperoxy hexane,t-hexylperoxy-2-ethylhexanoate, t-hexylperoxy isopropyl monocarbonate,t-butylperoxy laurate, t-butylperoxy isopropyl monocarbonate,t-butylperoxy-2-ethylhexyl monocarbonate,2,5-dimethyl-2,5-di-benzoylperoxyhexane, or the like can be given.

As specific examples of peroxy carbonates, di-n-propylperoxydicarbonate, diisopropyl peroxycarbonate, di-4-t-butylcyclohexylperoxycarbonate, di-2-ethylhexylperoxy carbonate, di-sec-butylperoxycarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexylperoxydicarbonate, diisopropyloxy dicarbonate, t-amylperoxyisopropylcarbonate, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexylcarbonate, 1,6-bis(t-butylperoxycarboxyloxy)hexane or the like can begiven.

In the invention, the above-mentioned radical polymerization initiatorsmay be used singly or in combination of two or more.

The content of the radical polymerization initiator in the compositionof the invention is preferably 0.01 to 10 parts by mass, more preferably0.1 to 5 parts by mass relative to 100 parts by mass of the total of thecomponents (A) to (H).

(Anti-Oxidant)

As the anti-oxidant, a phenol-based anti-oxidant, a phosphorus-basedanti-oxidant, a sulfur-based anti-oxidant, a vitamin-based anti-oxidant,a lactone-based anti-oxidant, an amine-based anti-oxidant or the likecan be given.

As the phenol-based anti-oxidant,tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propyonate]methane,β-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid stearyl ester,1,3,5-trimethyl-2,4,6-tri(3,5-di-t-butyl-4-hydroxybenzyl)benzene,tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate,tris[(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate,2,6-di-t-butyl-4-rnethylphenol,3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetra-oxa-spiro[5,5]undecane,tris(2,6-dimethyl-3-hydroxy-4-t-butylbenzyhisocyanurate or the like canbe given. As examples thereof, commercial products such as IRGANOX 1010,IRGANOX 1076, IRGANOX 1330, IRGANOX 3114, IRGANOX 3125, IRGANOX 3790(these IRGANOX products are manufactured by BASF Japan), CYANOX 1790(manufactured by American Cyanamid Company), SUMILIZER BHT, SUMILIZERGA-80 (these Sumilizer products are manufactured by Sumitomo ChemicalCompany, Ltd.) can be given. (These are product names.)

As the phosphorus-based anti-oxidant,tris(2,4-di-t-butylphenyl)phosphite,2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepine-6-yl]oxy]-N,N-bis[2-[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphine-6-yl]oxy-ethanamine,cyclic neopentanetetrayl bis(2,6-di-t-butyl-4-methylphenyl)phosphite,distearyl pentaerythritol diphosphite or the like can be given. Forexample, commercial products such as IRGAFOS 168, IRGAFOS 12, IRGAFOS 38(these IRGAFOS products are manufactured by BASF Japan Co., Ltd.), ADKSTAB 329K, ADK STAB PEP36, ADK STAB PEP-8 (these ADK products aremanufactured by ADEKA Corporation), Sandstab P-EPQ (manufactured byClariant International Ltd.), Weston 618, Weston 619G, Weston 624 (theseWeston products are manufactured by General Electric Company) or thelike can be used. (These are product names.)

As the sulfur-based anti-oxidant, dilauryl thiodipropionate, distearylthiodipropionate, dimyristyl thiodipropionate, laurylstearylthiodipropionate, pentaerythritol tetrakis(3-dodecyl-thiopropionate),pentaerythritol tetrakis(3-lauryl thiopropionate) or the like can begiven. For example, commercial products such as DSTP “Yoshitomi”, DLTP“Yoshitomi”, DLTOIB, DMTP “Yoshitomi” (these products are manufacturedby API Corporation), Seenox 4125 (manufactured by Shipro Kasei Co.,Ltd.), Cyanox 1212 (manufactured by American Cyanamid Company),SUMILIZER TP-D (manufactured by Sumitomo Chemical Company, Ltd.) or thelike can be used. (These product names.)

As the vitamin-based antioxidant, tocopherol,2,5,7,8-tetramethyl-2(4′,8′,12′-trimethyltridecyl)coumarone-6-ol or thelike can be given. For example, commercial products such as IRGANOX E201(manufactured by BASF Japan Co., Ltd.) or the like can be used.

As the lactone-based antioxidant, those disclosed in JP-A-H07-233160 andJP-A-H07-247278 can be used. Further, HP-136 (product name, manufacturedby BASF Japan Co., Ltd., compound name:5,7-di-t-butyl-3-(3,4-dimethylphenyl)-3H-benzofuran-2-one) or the likecan also be used.

As the amine-based antioxidant, commercial products such as IRGASTAB FS042 (manufactured by BASF Japan Co., Ltd.), GENOX EP (manufactured byCrompton Manufacturing Company, Ltd., Name of compound:Dialkyl-N-methylamineoxide) or the like can be given. (These are productnames).

These anti-oxidants can be used singly or in combination of two or more.The content of the anti-oxidant in the composition of the invention ispreferably 0.005 to 5 parts by mass, more preferably 0.02 to 2 parts bymass, relative to 100 parts by mass of the total of the components (A)to (H), in order not to hinder the advantageous effects of theinvention.

(Photostabilizer)

As the photostabilizer, an arbitrary photostabilizer such as a UVabsorber or a hindered amine-based photostabilizer can be used. Ahindered amine-based photostabilizer is preferable.

As specific examples of the hindered amine-based photostabilizer, ADKSTAB LA-52, LA-57, LA-62, LA-63, LA-67, LA-68, LA-77, LA-82, LA-87 andLA-94 (these LA products are manufactured by ADEKA Corporation), Tinuvin123, 144, 440, 662, 765, 770DF, Tinuvin XT 850 FF, Tinuvin XT 855 FF,Chimassorb 2020, 119, 944 (these Tinuvin products are manufactured byBASF Japan Co., Ltd.), Hostavin N30 (manufactured by Hoechst AG),Cyasorb UV-3346, UV-3526 (manufactured by Cytec Technology, Ltd.), Uval299 (manufactured by GLC Co., Ltd.), Sanduvor PR-31(manufactured byClariant International Ltd.) or the like can be used (these are allproduct names).

As specific examples of the UV absorber, Adekastab LA-31, AdekastabAdekastab LA-36, Adekastab LA-29, Adekastab Adekastab LA-F70, Adekastab1413 (these Adekastab products are manufactured by ADEKA Corporation),Tinuvin P, Tinuvin 234, Tinuvin 326, Tinuvin 328, Tinuvin 329, Tinuvin213, Tinuvin 571, Tinuvin 765, Tinuvin 1577ED, Chimassorb 81, Tinuvin120 (these products are manufactured by BASF Japan Co., Ltd.), or thelike can be used. Among these, Tinuvin series manufactured by BASF JapanCo., Ltd. are preferable, with Tinuvin 765 being more preferable.

These photostabilizers can be used singly or in combination of two ormore. The content of the photostabilizer in the composition of theinvention is preferably 0.005 to 5 parts by mass, more preferably 0.02to 2 parts by mass, relative to 100 parts by mass of the total of thecomponents (A) to (H) in order not to hinder the advantageous effects ofthe invention.

(Mold-Releasing Agent)

For an internal mold-releasing agent, it is required to have thefollowing properties, i.e, it is dissolved and well-dispersed in a(meth)acrylate compound. Further, its molecular movement can easilyoccur during curing the composition, since it is in a molten state witha low viscosity. When the composition cures completely, it separatesfrom resin components being curing completely, and is present between amold and components cured, whereby it has mold-releasing property. Inaddition, when released from a mold, it has a low viscosity in a moltenstate to have a high mold-releasing property. Although no specificrestrictions are imposed on the internal mold-releasing agent, analiphatic compound is desirable.

The aliphatic compound used as an internal mold-releasing agent has amelting point of preferably −40° C. to 180° C., and further preferably−30° C. to 180° C., By using the aliphatic compound having a meltingpoint of −40° C. or higher, there is no fear that the compound isgasified during curing and bubbles are generated in a product to makeexternal appearance poor, and it exhibits good mold-releasing property.By using an aliphatic compound having a melting point of 180° C. orlower, solubility is improved to obtain good external appearance andmold-releasing property.

As the above-mentioned aliphatic compound, a compound represented by thefollowing formula (V) is preferable.

wherein in the formula (V), R⁴ is an aliphatic hydrocarbon groupincluding 6 to 30 carbon atoms.

W is a hydrogen atom, a metal atom or a hydrocarbon group including 1 to8 carbon atoms.

If W is a metal atom, O and W are ionically bonded.

The aliphatic hydrocarbon group represented by R⁴ in the formula (V) maybe linear or branched. As for the bonding state in the molecular chain,it may comprise only a single bond or may comprise a multiple bond,Specifically, a saturated aliphatic hydrocarbon groups or an unsaturatedaliphatic hydrocarbon groups may be given. The number of a multiple bondin the aliphatic unsaturated hydrocarbon group may be one or more thanone.

The number of carbon atoms of the hydrocarbon group of R⁴ is 6 to 30. Ifthe number of carbon atoms is less than 6, the compound is evaporated orthe like at the time of curing, and as a result, no aliphatic compoundcan be present between the mold and the material. Therefore, moldreleasing property may not be exhibited or air bubbles may remain in thematerial. If the number of carbon atoms exceeds 30, the mobility of thematerial is lowered, and an aliphatic compound is incorporated into thematerial to cause the material to be opaque or to inhibit mold-releasingproperty from being exhibited. The number of carbon atoms of R⁴ ispreferably 6 to 26, more preferably 8 to 22.

As the metal atom in W of the formula (V), an alkali metal such aslithium and sodium, an alkaline earth metal such as magnesium andcalcium, zinc and aluminum can be given.

When W is an alkali metal or aluminum, the valence thereof becomesdivalence or higher. Therefore, the formula (V) of the aliphaticcompound is represented by (R⁴—CO—O)_(q)—W, and q is 2 to 4.

The aliphatic hydrocarbon group in W of the formula (V) may be linear orbranched. As for the bonding state in the molecular chain, it maycomprise only a single bond or may comprise a multiple bond.Specifically, a saturated aliphatic hydrocarbon group or an unsaturatedhydrocarbon group may be given.

The number of a multiple bond in the aliphatic unsaturated hydrocarbongroup may be one or more than one. The number of carbon atoms of thealiphatic hydrocarbon group of W is 1 to 8. If the number of carbonatoms is 8 or more, an increase in melting point or a lowering insolubility of the aliphatic compound may be caused. As a result, thealiphatic compound may be incorporated into the resin components or maybe localized in the resin components at the time of curing, wherebymold-releasing property may not be exhibited or a molded product maybecome opaque. The number of carbon atoms of the aliphatic hydrocarbongroup of W is preferably 1 to 6.

In order to allow the aliphatic compound to exhibit good mold releasingproperty, when W in the aliphatic compound represented by the formula(V) is a hydrogen atom, R⁴ is preferably an aliphatic hydrocarbon groupincluding 6 to 20 carbon atoms. If W is a metal atom, R⁴ is preferablyan aliphatic hydrocarbon group including 6 to 18 carbon atoms. If W isan aliphatic hydrocarbon group, the total number of carbon atoms of R⁴and W is preferably 7 to 30.

The content of the mold-releasing agent in the invention is 0.01 to 10parts by mass, preferably 0.01 to 5 parts by mass, relative to 100 partsby mass of the total of the components (A) to (H). If the content of themold releasing agent exceeds 10 parts by mass, there may be apossibility that transferability of a mold shape or shape stability toheat cannot be kept. On the other hand, if the content of the moldreleasing agent is less than 0.01 part by mass, there may be apossibility that mold releasing property cannot be obtained.

The composition of the invention can be obtained by mixing theabove-mentioned components (A) to (H) with a prescribed mixing ratio.The mixing method is not particularly restricted, and a known arbitrarymeans such as an agitator (mixer) can be used. In addition, thecomponents can be mixed at normal temperature, while cooling or withheating under normal pressure, under reduced pressure or under pressure.

The composition of the invention is a suitable material for producing areflector for an optical semiconductor, and can reduce curvature orun-filling of a lead frame molded product that can occur at the time ofproducing a light-emitting device. Further, the mass-producibility andlifetime of light reflectance of the light-emitting device can beimproved, and the amount of burrs formed after molding can be reduced,whereby removal of burrs can be omitted. As a result, the quality of themolded product after a treatment for resistance to electrolysis can beimproved.

Further, the composition of the invention is a material that can prolongthe time for which it can be used under the temperature of molding.

A cured product can be produced by using the composition of theinvention by transfer molding, compression molding or injection molding.

In the case of transfer molding, by using a transfer molding machine,molding can be conducted with a clamping force of 5 to 20 kN, at amolding temperature of 100 to 190° C. for a molding time of 30 to 500seconds, preferably at a molding temperature of 100 to 180° C. for amolding time of 30 to 180 seconds. In the case of compression molding,by using a compression molding machine, molding can be conducted at amolding temperature of 100 to 190° C. for 30 to 600 seconds, preferablyat a molding temperature of 110 to 170° C. for 30 to 300 seconds. Forany of the molding methods, post-curing may be conducted, for example,at a temperature of 150 to 185° C. for 0.5 to 24 hours.

By using liquid injection molding, it can be molded at a clamping forceof 10 kN to 40 kN, at a molding temperature of 100 to 190° C. for amolding time of 30 to 500 seconds, preferably at a molding temperatureof 100 to 180° C. for 20 to 180 seconds.

When the composition of the invention is molded by transfer molding,compression molding, liquid resin injection molding, insert molding orthe like, preliminary polymerization may be conducted.

[Method for Producing Thermoset Resin]

The method for producing a thermoset resin of the invention comprisesthe following steps (1) to (4):

(1) A step of supplying the thermosetting composition of the inventionto a plunger;

(2) A step of filling the thermosetting composition that is filled inthe plunger in a cavity of a mold;

(3) A step of heat curing the thermosetting composition in the cavity;and

(4) A step of taking out the heat-cured thermoset resin

The thermosetting composition of the invention has a low viscosity.Therefore, the liquid components thereof can be filled in a gap of 1 μmwhen filling is conducted while applying pressure in the mold. On theother hand, since the thermosetting composition of the inventioncontains spherical silica or a white pigment, during the process offilling the thermosetting composition in a cavity in the mold, the“liquid releasing” phenomenon in which only resin components of thethermosetting composition are filled may occur. Further, the compositionof the invention is thermosetting, it should not be heated untilimmediately before molding, and it is required to be sufficiently heatedat the time of molding. In addition, there may be a possibility thatcuring is not conducted completely if oxygen is present at the time ofcuring by heating.

By the molding method of the invention, by using a plunger-typeinjection molding machine provided with a plunger instead of a screwtype injection molding machine, a phenomenon of leakage (back flow) orrelease of a liquid can be prevented even in the case of a low-viscouscomposition. Further, the composition is cured by heat within thecavity, thermosetting in the absence of oxygen is possible. Therefore,the molding method according to the invention is preferable as a methodfor molding the thermoset resin of the invention.

FIG. 1 is a view showing one embodiment of a molding machine with whichthe injection molding method of the invention can be implemented.

The molding machine shown in FIG. 1 is an injection molding machinehaving a plunger mechanism that extrudes the thermosetting compositionof the invention to a mold, and is provided with a filling apparatus 10having a plunger 11 shown in FIG. 1 and a mold 20 having a cavity 21shown in FIG. 2(A). Although not shown, it is provided with adecompressor as a degassing means connected to the pores for degassingthe cavity 21 in the mold 20, a heating apparatus as a heating meansconnected to the mold 20, and a cooling apparatus. A molding material isa thermoset resin of the invention.

As the filling apparatus 10, a known filling apparatus provided with aplunger can be used. Normally, the filling apparatus 10 provided withthe plunger 11 is, as shown in FIG. 1, provided with a feed part and anon-return function. By allowing a screw 12 to rotate, materials thathave been input from an input port not shown are fed, stirred and mixed.In this embodiment, since a raw material composition that is ahomogenous liquid is input, stirring and mixing are not necessary,Therefore, no screw configuration is necessary, and only the rawmaterial feeding from the inlet and provision of the non-returningfunction may be enough.

In the method for molding a thermosetting composition of the invention,in the process of filling in the cavity of a mold a thermosettingcomposition that has been supplied to the plunger, the thermosettingcomposition is filled in the cavity of a mold through a flow path ofwhich the temperature has been controlled to 50° C. or lower. If themolding method of the invention is implemented by using the apparatusshown in FIG. 2, the above-mentioned flow path corresponds to the flowchannel 13 of the raw material composition in the filling apparatus 10and the introduction channel in the mold 20. The flow path may becontrolled to have a temperature of 50° C. or lower by using the coolingpart 14.

In the method for molding a thermosetting composition of the invention,during a process in which a thermosetting composition filled in theplunger is filled in the cavity of a mold by means of the plunger, agate system in which flow of a curable liquid and transfer of heat areshut off is provided to the flow path between the plunger and thecavity. Hereinbelow, the molding method of the invention will beexplained with reference to FIG. 2.

When the molding method of the invention is implemented by using theapparatus shown in FIG. 2, a needle 223 and an opening 222 correspond tothe above-mentioned gate system. As mentioned above, the needle 223moves to the movable die 23, and closes the opening 222, whereby the anintroduction channel 221 is separated in front of a heating part 22A.The composition that has been introduced into the introduction channel221 is accumulated in a cooling part 22B, whereby flow of thecomposition and transfer of heat can be shut off. As the system forshutting off the flow of the composition and transfer of heat, a valvegate system, a shut-off nozzle system or the like can be given.

The heating apparatus is an apparatus that heats the heating part 22Aand the movable mold 23. By heating the heating part and the movablemold, it is possible to allow the temperature in the cavity 232 (oftenreferred to as the “cavity temperature”) to be a predeterminedtemperature. In the molding method of the invention, the moldtemperature of the cavity part is allowed to be 100° C. or higher and180° C. or lower.

The cooling apparatus is an apparatus that cools the flow path of theraw material composition. Specifically, the filling apparatus 10 and thecooling part 22B of the mold 20 is preferably cooled to 10° C. or higherand 50° C. or lower.

In the case of injection molding, the needle 15 in FIG. 1 and the needle223 in FIG. 2, and the flow channel 13 in FIG. 1 and the introductionchannel 221 in FIG. 2, respectively correspond,

The molding method of the thermoset resin by using the above-mentionedmolding machine comprises a step of supplying a prescribed amount of athermosetting composition to a plunger (supply step), a step of fillingby means of the plunger the thermosetting composition filled in theplunger in the cavity of a mold (filling step), a step of heat curingthe thermoset resin in the cavity (curing step) and a step of taking outa cured product obtained by heat curing the thermoset resin(mold-releasing step), for example.

(Supply Step)

When molding is conducted by transfer molding or compression, weighingcan be conducted by inserting into a plunger part in the mold anappropriate amount of a material by using a supply apparatus such as asyringe.

When molding is conducted by injection molding, the raw materialcomposition is supplied from an inlet (not shown) to the fillingapparatus 10 shown in FIG. 1 The supplied raw material composition isextruded to a flow channel 12, and a prescribed amount is weighed by theplunger 11. After the completion of the measurement or before theinjection, the screw 12 advances, and exhibits a function as anon-return valve when the plunger 11 operates. During this period oftime, since the flow path is cooled by the cooling apparatus, the rawmaterial composition flows smoothly without being cured.

(Filling Step)

The filling step corresponds to FIG. 2(B).

When injecting the thermosetting composition to the cavity, it isrequired to release the air in the cavity through a vent, or todecompress inside of the cavity through pores such as a decompressiontube 240 in FIG. 2 that is connected to a decompression apparatus andenable to decompress inside of the cavity. The reason is that, duringthe process of injecting a thermosetting composition to a cavity andfilling it in the cavity completely, the vent serves to release the airin the cavity, and decompression in the cavity enables complete fillingby allowing the inside of the cavity to be free from the presence ofair. If these mechanisms are not present, another mechanism that allowsthe air in the cavity to be released at the time of filling the rawmaterial will become necessary (e.g. vent mechanism).

In order to mold a thermosetting composition, first, the movable mold 23is allowed to approach the fixed mold 22, and clamping is conducted(FIG. 2(A)). At a position where an elastic member 238 of the movablemold 23 abuts an elastic member 224 of the fixed mold 22, movement ofthe movable mold 23 once stops.

Filling of a thermosetting composition in the cavity is conducted byopening the gate of a gate system (i.e. the needle 223 is moved to theside of the fixed mold 22), followed by filling of the thermosettingcomposition in the cavity 21 of the mold. A heating part 22A provided inthe movable mold 23 and the fixed mold 22 are heated all the time, andset such that the cavity temperature becomes 60° C. or higher,preferably 100° C. or higher and 180° C. or lower, and particularlypreferably 110° C. or higher and 170° C. or lower.

Meanwhile, when an injection molding machine is used, when injectionfrom an injection part to the cavity start, the nozzle of a shut-offnozzle (in some cases, a valve gate) is opened, the plunger in aninjection part is allowed to move, whereby the thermosetting componentsare injected into the cavity. When a transfer molding machine is used,all of the raw materials from the inside of the plunger to the cavitypart are cured. Therefore, the flow of the raw materials to the cavityis only required to be possible, and there is no necessity that transferof heat is shut off.

(Curing Step)

The curing step corresponds to FIG. 2(C).

When filling of the raw material composition to the cavity 21 iscompleted, curing of the raw material composition simultaneously starts.In order to improve transferability of a molded product, it is necessaryto cure by applying a prescribed pressure. That is, it is preferred thatthe plunger 11 be in a state that has been pressurized at 1.0 MPa ormore and 15 MPa or less. This pressure that is applied to the rawmaterial composition in order to improve the transferability is calledholding pressure.

In the curing step, it is preferred that the injection pressure of athermosetting composition be increased after the start of curing, andpressure holding be conducted before completion of curing, and aftercompletion of the pressure holding, the gate of the gate system isclosed to conduct heat curing. Specifically, the gate is closed byadvancing the needle 223 and closing the opening part 222. During themolding process, the cooling apparatus is operated, the entire area ofthe flow channel of the raw material composition, i.e. the fillingapparatus 10 of the molding machine and the cooling part 22B provided inthe fixed mold 22 of the mold 20 are cooled. At this time, it ispreferred that the entire area of the flow channel be kept at 10° C. orhigher and 50° C. or lower, with 30° C. or lower being particularlypreferable.

Hereinbelow, an explanation will be made on the pressure holding in theplunger 11 and timing when the pressure holding starts. FIG. 3 is a viewshowing the relationship between the viscosity of the raw materialcomposition and the time in the present embodiment. In FIG. 3, theperiod P1 from the injection of the raw material to the cavity to thecompletion of the filling corresponds to an introduction period duringwhich heat is applied to the raw material and the curing starts. Thecuring process is divided into two steps; i.e. the initial curing periodP2 during which the material starts to be cured by applying heat and thematerial is cured and the later curing period P3 during which the curingis completed. During the introduction period P1, viscosity of the rawmaterial composition does not change and is kept to be low. During theinitial curing period P2, significant viscosity change from lowviscosity to high viscosity is observed. During the later curing periodP3, the viscosity of the raw material composition increase at a slowerpace in a high viscosity state.

In the initial curing period P2, not only a change in viscosity of a rawmaterial composition associated with its change from a liquid to a solidoccurs, but also the volume thereof is changed, followed by shrinkage.As a result, as long as a pressure is not applied to the raw materialcomposition, a molded product becomes poor in transferability. In orderto improve transferability, it is required to apply a pressure to theraw material composition (pressure holding) to allow the raw materialcomposition to adhere to the mold 20, as well as to compensate the rawmaterial composition from the gate part.

However, in the case of a low viscous material as in the case of the rawmaterial composition of the present embodiment, when a pressure isapplied in the state where the viscosity of the raw material is low, dueto its low viscosity, unfavorable molding associated with formation ofburrs (specifically, the material leaks from a gap between the fixedmold 22 and the movable mold 23 and is cured) occurs or a poor operationof a knockout pin is caused by infiltration of the raw materialcomposition into a gap or the like around the knockout pin, or othertroubles occur. On the other hand, even if a pressure is applied in thestate where the viscosity is increased in the initial curing period P2or in the later curing period P3, a thermosetting composition cannot bedeformed by compression due to a high viscosity of the raw materialcomposition, so as not to improve transferability. Therefore, in orderto obtain a molded product having a high transferability, the timing atwhich pressure holding starts (pressure holding start time T) isrequired to be in conformity with the timing at which the introductionperiod P1 of the curing step is shifted to the initial curing period P2.

Here, if the viscosity of the raw material composition in the cavity 21can be detected, the pressure holding start time T can be determined.However, in order to measure the viscosity of the raw materialcomposition, it is necessary to incorporate an apparatus for measuringthe raw material composition viscosity in the cavity 21 of the mold 20.This leads to an increase in size of the mold 20, complication of themechanism, a significant increase in production cost, and hence, is notrealistic.

The raw material composition in the present embodiment starts to shrinkwhen the viscosity thereof is increased in the initial curing period P2.Therefore, if the time when shrinkage starts is detected, the pressureholding time T can be appropriately determined.

By conducting pressure holding under the above-mentioned conditions inthe curing step, formation of sink marks or deformation of a moldedproduct can be prevented, and transferability can be improved.

After completion of pressure holding for a certain period of time, asshown in FIG. 2(C), the needle 223 is advanced to block the opening part222, and heated for a certain period of time so that a non-cured part isnot generated, whereby the raw material composition is completely cured.

Here, by advancing the plunger 11 to fill the cavity 21 of the mold 20with a thermosetting composition, and the time required for filling istaken as t₁. When the filling is completed, the plunger 11 stops.Further, when curing of the raw material composition starts, shrinkageof a thermosetting composition starts simultaneously. Therefore, aftercompletion of the filling step, the plunger 11 starts to advance again.The time taken from the completion of the filling step to the re-startof advancement of the plunger 11 is taken as t₂, and the time taken forallowing the composition to be completely cured by further heating istaken as t₃, t₁+t₂+t₃ (the total time required for the filling step andthe heat-curing step) is preferably 0.2 minute to 3 minutes, with 0.2minute to 2 minutes being further preferable. If t₁+t₂+t₃ is less than0.2 minute, un-curing may occur. t₁+t₂+t₃ of 3 minutes or longer isunfavorable in respect of mass producibility.

(Mold Releasing Step)

The mold releasing step corresponds to FIG. 2(D).

By releasing the movable mold 23 from the fixed mold 22, a cured productin the cavity can be taken out. If the mold releasing property is poor,an ejector mechanism may be appropriately provided in the mold.

[Cured Product]

The cured product of the invention (thermoset resin) can be obtained bycuring by subjecting the thermosetting composition of the inventionexplained above to polymerization with heat. Preferably, it is a curedproduct obtained by molding by the production method of the invention.

The cured product of the invention can be preferably used as a reflectoror the like for use in an optical semiconductor light-emitting device. Areflector obtained by using the cured product of the invention does notexperience lowering in reflectance even when used for a long period oftime. Further, it has a high reflectance in the visible range, hasexcellent heat resistance and weatherability, and is improved inadhesiveness to peripheral members.

The reflector of the invention has high reflectance in the visiblerange, and lowering in reflectance is small even when used for a longperiod of time. The light reflectance at a wavelength of 450 nm of thereflector of the invention is preferably 85% or more, more preferably90% or more and further preferably 93% or more. The lowering in lightreflectance from the initial light reflectance after the deteriorationtest conducted at 150° C. for 1,000 hours is preferably 20% or less,more preferably 15% or less, and further preferably 10% or less. Thelight reflectance can be determined by the method described in theExamples.

[Optical Semiconductor Light-Emitting Device]

The optical semiconductor light-emitting device of the inventionincludes the reflector of the invention as explained above. As for otherconfigurations of the optical semiconductor light-emitting device, knownconfigurations can be adopted.

The substrate for mounting the optical semiconductor device of theinvention and the optical semiconductor light-emitting device of theinvention will be further explained with reference to the drawings. FIG.4 is a schematic cross-sectional view showing one embodiment of thesubstrate for mounting the optical semiconductor device of the inventionand the optical semiconductor light-emitting device, FIG. 4(a) shows alead frame 510.

FIG. 4(b) shows a substrate 520 for mounting an optical semiconductordevice with a reflector 521 obtained by molding a resin molded productin the lead frame 510 shown in FIG. 4(a). The substrate 520 for mountingan optical semiconductor device has a concave part constituted of abottom surface composed of the lead frame 510 and the reflector 521 andan inner peripheral side surface composed of the reflector 521. Theresin molded body constituting the reflector 521 is obtained by curingthe composition of the invention.

FIG. 4(c) shows an optical semiconductor light-emitting device 530 inwhich the optical semiconductor device 531 is mounted on the substratefor mounting an optical semiconductor device shown in FIG. 4(b), theoptical semiconductor device 531 and another lead frame on which theoptical semiconductor device 531 is not mounted are bonded by means of awire 532, and the concave part is sealed with a transparent resin(sealing resin) 533. The inside of the sealing resin may contain afluorescent product 534 for converting emitted light of blue or the liketo white.

Further, it shows a schematic cross-sectional view showing anotherembodiment of the substrate for mounting an optical semiconductor deviceand the optical semiconductor light-emitting device of the invention.

FIG. 5(a) shows a lead frame 10.

FIG. 5(b) shows a substrate 620 for mounting an optical semiconductordevice in which a resin molded product is molded as a reflector 621between the lead frames 610 shown in FIG. 5(a), The substrate 620 formounting an optical semiconductor device is provided with the reflector621 between the lead frame 610 and the lead frame 610.

FIG. 5(c) shows an optical semiconductor light-emitting device 630provided with the substrate for mounting an optical semiconductor deviceshown in FIG. 5(b). The optical semiconductor device 631 is mounted onthe lead frame 610, and electrically connected by means of a bondingwire 632. Thereafter, a sealed resin part composed of a transparentsealing resin 633 is molded by curing comprehensively by transfermolding, compression molding or the like, thereby to seal the opticalsemiconductor device 631, and dicing is conducted to allow it to bepieces. In the inside of the sealed resin, a fluorescent body 634 forconverting the emission color from blue to white may be contained.

The dimension and shape of each part of the substrate for mounting theoptical semiconductor device are not particularly restricted, and can beappropriately set. The sealing resin (sealing material) is composed ofan epoxy resin, a silicone resin, an acrylate resin or the like, forexample.

EXAMPLES

The present invention will be explained in more detail with reference tothe following examples, which should not be construed as limiting thescope of the invention.

Examples 1 to 30 and Comparative Examples 1 to 10

A thermosetting composition was prepared by using raw materials and witha composition ratio shown in Tables 1 to 4. Molded products wereobtained under the molding conditions A or B.

For preparation of a composition, first, the liquid components and theadditive components were respectively weighed, and these components weremixed and stirred. Subsequently, inorganic components were respectivelyweighed and added, followed by stirring to obtain a composition. Theinorganic components were incorporated in the order of the component(H), the component (G), the component (C) and the component (B).

As the stirring apparatus, a stirring apparatus that enables stirring byrotation and revolution was used. During the stirring, the rotation wasconducted at a speed of 1,000 rpm and the revolution was conducted at aspeed of 2,000 rpm, and the stirring was conducted for 1 minute.

[LTM Molding (Molding Conditions A)]

Molding machine: Liquid transfer molding machine G-Line, manufactured byApic Yamada Corporation.

Flow channel temperature of a low-temperature part: 25° C.

Flow channel and shut-off method: Manual shut-off by using a syringe

Flow channel temperature of a high-temperature part and cavitytemperature: The temperature was set at 150° C. when Perbutyl E was usedas the additive, and the temperature was set at 130° C. when Perhexa HCwas used as the additive.

Filling time: 10 seconds

Filling pressure: 2 MPa (priority was on the filling time)

Pressure holding time: 15 seconds

Pressure at the time of pressure holding: 5 MPa

Curing time: 90 seconds

[LIM Molding (Molding Conditions B)]

Molding machine: Liquid thermoset resin injection molding machineLA-40S, manufactured by Sodic Co., Ltd.

Flow channel temperature of the low-temperature part: 15° C.

Method for shutting off the flow channel and heat shut off method:Shut-off nozzle was used.

Temperature of flow channel of a high-temperature part and the cavitytemperature: the temperature was set at 150° C. when Perbutyl E was usedas the additive, and the temperature was set at 130° C. when Perhexa HCwas used as the additive.

Filling time: 10 seconds

Pressure at the time of filling: 2 MPa (priority was put on the fillingtime)

Pressure holding time: 15 seconds

Pressure at the time of pressure holding: 5 MPa

Curing time: 90 seconds

The components used for preparing the thermosetting composition were asfollows:

[Component (A): (Meth)acrylate Compound]

AM: Adamantyl methacrylate (M-104, manufactured by Idernitsu Kosan Co.,Ltd. Viscosity at 25° C.: 10 mPa·s)

IBMA: 1-Isobornyl methycrylate (IB-X, manufacture by Kyoeisha ChemicalCo., Ltd. Viscosity at 25° C.: 10 mPa·s)

[Components (D), (E) and (F): (Meth)acrylate Compound]

LA: Lauryl acrylate (SR335, manufactured by Alkerna Co., Ltd.)

StMA: Stearyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)

SR351: Trimethylol propane triacrylate (manufactured by Alkema Co.,Ltd.)

GMA: Glycidyl methacrylate (Blemmer GH, manufactured by NOF Corporation)

DCP: Tricyclodecane dimethanol dirnethacrylate (manufactured byShin-Nakamura Chemical Co., Ltd.)

A-DON-N: 1,10-decanediol diacrylate (manufactured by Shin-NakamuraChemical Co., Ltd.)

3000 MK: Bisphenol A diglycidyl ether methacrylic acid adduct (3000 MK,manufactured by Kyoeisha Chemical Co., Ltd.)

MMA: Methyl methacrylate (manufactured by Hiroshima Wako Co., Ltd.)

[Component (B): Spherical Silica]

CRS1085-SF630: Spherical silica having an average particle size (D50) of15 μm (manufactured by Tatsumori Ltd.)

CR1015-MSR35TS: Spherical silica having an average particle size (D50)of 15 μm (manufactured by Tatsumori Ltd.)

CRS1035-LER4: Spherical silica having an average particle size (D50) of2 μm (manufactured by Tatsumori Ltd.)

TS12-046HA: Spherical silica having an average particle size (D50) of 15μm (Nippon Steel Sumikin Material Co., Ltd, Micron Company)

[Component (C): White Pigment]

PC-3: Titanium oxide having an average particle size of 0.2 μm(manufactured by Ishihara Sangyo Kabushiki Kaisha)

[Component (G): Plate-Like Filler]

TP-A: Talc having an average particle size of 5 pm (manufactured by FujiTalc Industries, Co., Ltd.)

[Component (H): Nano Particles]

R711: Fumed silica having a particle size of 5 to 50 nm (manufactured byNippon Aerosil Co., Ltd.)

[Additive]

Tinuvin765: UV absorber (manufactured by BASF Japan Co., Ltd.)

StMg: Magnesium stearate (manufactured by NOF Corporation)

StZn: Zinc stearate (manufactured by Dainichi Chemical Industry)

Perbutyl E: Organic peroxide (manufactured by NOF Corporation)

Perhexa HC: Organic peroxide (manufactured by NOF Corporation)

For the composition prepared and the molded product obtained, thefollowing evaluation was conducted. The results are shown in Tables 1 to4.

(1) Viscosity Measurement Method

For the prepared composition, the melt viscosity was measured by meansof a visco-elastic measurement apparatus under the following conditions:

Name of apparatus: Physica MCR301 manufactured by Anton Paar Company

Measurement method: Plate-plate

Plate diameter: 25 mmφ

Temperature: 25° C.

Distance between plates: 0.6 mm

Shear velocity: 1 to 200 (1/s)

In this shear velocity region, the shear viscosity at 10 (1/s) and 100(1/s) are taken as the viscosity.

At the time of measurement, when measurement could not be conducted dueto occurrence of slippage, in some cases, a normal force was applied ina range where the thickness was not changed.

(2) Stoageability at Normal Temperature

The composition thus prepared was allowed to stand at 25° C. for 2 days.Thereafter, the composition was molded by using the mold. When short orburrs were not generated, the composition was evaluated as “◯”, wheneither short or buns was generated, the composition was evaluated as“Δ”, and when both were generated, the composition was evaluated as “×”.

(3) Evaluation on Mold and Good Moldability

As for the mold for evaluating rnoldability, a mold with a width (10mm)×a length (50 mm)×a thickness (1 mm) and having a vent at the flowend part with a thickness nm)×a length (10 mm)×a thickness (0.03 mm) wasused. As for the mold for evaluating properties, a mold with a width (50mm)×a length (50 mm)×a thickness (2 mm) was used.

(3-1) Evaluation of Moldability

As for evaluation of moldability, occurrence of short was confirmed. Thetemperature of the mold was set to a predetermined temperature, andduring a step of filling for 10 to 15 seconds, generation of voids oroccurrence of un-filling in a molded product were confirmed visually.When both generation of voids and un-filling were occurred, themoldability was evaluated as ×, when either of them occurred, themoldability was evaluated as Δ, and when neither of them occurred, themoldability was evaluated as ◯.

(3-2) Formation of Burrs

The temperature of the mold was set to a predetermined temperature, andduring a step of filling for 10 to 15 seconds, formation of burrs wasvisually confirmed. When burrs were formed such that they exceeded theend part of the vent or burrs were formed from parts other than thevent, formation of burrs was evaluated as “×”, when either of themoccurred, formation of burrs was evaluated as “Δ”, and when neither ofthem was occurred, the formation of burrs was evaluated as “◯”.

(4) Measurement of Light Reflectance

For the resulting molded product, using a spectrophotometer (productname: UV-2400PC) to which a multi-purpose large-sized sample chamberunit (product name: MPC-2200, manufactured by Shimadzu Corporation) wasattached, the light reflectance of a sample piece of a cured product wasmeasured.

(5) Energization Test of LED (Evaluation of Light Resistance)

On a LED package on which a blue-emitting LED (product name: OBL-CH2424manufactured by GeneLite Inc.) was mounted, a test piece of a curedproduct was fixed, and was allowed to emit light by passing electriccurrent for 1 week at an environment temperature of 60° C. at a currentvalue of 150 mA. The LED light-irradiated surface of the test piece of acured product was visually observed, and evaluated by the followingstandards.

◯: No discoloration

x: Color of the light-irradiated surface was changed to be brown

(7) Bending Elastic Modulus and Bending Strength

For the obtained molded product, the bending elastic modulus and thebending strength were measured in accordance with IS0178.

(8) Evaluation of Heat Resistance

After measuring the initial light reflectance of the test piece of thecured product, the test piece was heated in an oven at 180° C. for 72hours. Then, the light reflectance of the test piece after the heatingwas measured. When the difference was less than 5%, the heat resistancewas evaluated as ◯, when the difference was 5% or more and less than10%, the heat resistance was evaluated as Δ, and when the difference was10% or more, the heat resistance was evaluated as ×.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 RawMonomer AM 6 8 7 6 7 material IBMA 6 7 6 8 8 LA 6 6 7 6 5 5 6 4 4 5 StMASR351 0.8 0.8 GMA 2.3 2.2 2 2 3 3 3 2 2 3 DCP 3 5 A-DOD-N 5 6 6 6 53000MK 5 MMA Silica CRS1085- 75 75 60 60 60 55 60 70 65 SF630 CRS1015-60 MSR35TS CRS1035- LER4 TS12- 046HA White PC-3 10 10 10 10 10 15 10 1010 10 Talc TP-A25 10 10 10 10 10 5 10 Additive Tinuvin765 0.5 0.5 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 StMg 1.5 1.5 1.5 1.5 StZn 1 1.5 1.5 1 2 1.5R711 1 2 1 4 3 1 Perbutyl E 0.18 0.25 0.23 0.23 Perhexa HC 1 0.8 1 0.8 11 CEL-W-7005 Total [mass %] 100 100 100 100 100 100 100 100 100 100Produc- Molding method LTM LTM LTM LTM LTM LTM LTM LTM LTM LTM tionWhether the flow channel Oc- Oc- Oc- Oc- Oc- Oc- Oc- Oc- Oc- Oc- methodis shut off or not curred curred curred curred curred curred curredcurred curred curred Whether the flow channel Not Not Not Not Not NotNot Not Not Not is blocked or not oc- oc- oc- oc- oc- oc- oc- oc- oc-oc- curred curred curred curred curred curred curred curred curredcurred Results of Occurrence of short ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ evaluationFormation of burrs Δ Δ ◯ ◯ ◯ ◯ ◯ Δ ◯ ◯ Storagiblity at normal X X Δ Δ ◯◯ ◯ ◯ ◯ ◯ temperature Shear  10(1/s) 13 13 12 12 15 20 20 8 10 15viscosity 100(1/s) 2 2 3 3 4 4 6 1 2 5 [Pa · s] Light reflectance [%] 9494 94 94 94 95 94 94 04 94 Bending elastic modulus [MPa] 7500 7500 65006500 6500 7000 6500 6000 6000 6500 Bending strength [MPa] 70 70 45 45 4545 45 70 50 45 Heat resistance ◯ ◯ Δ Δ ◯ ◯ Δ ◯ ◯ ◯ Light resistance ◯ ◯◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

TABLE 2 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18 Ex. 19Ex. 20 Raw Monomer AM 6 7 4.5 15.75 6 material IBMA 6 8 6 12.8 13.6 LA 56 4 5 5 4.5 6.4 11.25 11.25 6 StMA SR351 GMA 3 3 2 3 3 2.25 3.2 6.756.75 3 DCP A-DOD-N 6 6 5 6 9.6 11.25 13.5 3000MK 5 3.75 6 MMA SilicaCRS1085- SF630 CRS1015- 60 60 65 45 45 48 38 MSR35TS CRS1035- 15 15 1715 LER4 TS12- 35 35 60 046HA White PC-3 10 10 10 10 10 10 10 10 10 10Talc TP-A25 10 10 5 10 10 10 5 10 10 10 Additive Tinuvin765 0.5 0.5 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 StMg 1.5 1.5 1.5 1.5 1.5 1.5 StZn 1.5 1 1.51.5 R711 2 2 0.5 2 3 3 0.5 3 3 3 Perbutyl E 0.23 0.23 0.23 0.23 0.230.23 Perhexa H 1 0.8 1 1 CEL-W-7005 Total [mass %] 100 100 100 100 100100 100 100 100 100 Produc- Molding method LIM LIM LIM LIM LIM LIM LIMLIM LIM LIM tion Whether the flow channel Oc- Oc- Oc- Oc- Oc- Oc- Oc-Oc- Oc- Oc- method is shut off or not curred curred curred curred curredcurred curred curred curred curred Whether the flow channel Not Not NotNot Not Not Not Not Not Not is blocked or not oc- oc- oc- oc- oc- oc-oc- oc- oc- oc- curred curred curred curred curred curred curred curredcurred curred Results of Occurrence of short ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯evaluation Formation of burrs ◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ ◯ Storagiblity at normal◯ ◯ ◯ ◯ ◯ ◯ Δ Δ Δ ◯ temperature Shear  10(1/s) 20 40 12 14 15 50 14 8 845 viscosity 100(1/s) 5 9 3 3 3 15 3 2 2 10 [Pa · s] Light reflectance[%] 94 94 94 94 94 94 94 94 94 94 Bending elastic modulus [MPa] 65006500 6500 6500 6500 13000 5500 4000 4000 5500 Bending strength [MPa] 4545 50 45 45 40 40 35 35 40 Heat resistance ◯ Δ ◯ ◯ ◯ Δ ◯ ◯ ◯ Δ Lightresistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

TABLE 3 Ex. 21 Ex. 22 Ex. 23 Ex. 24 Ex. 25 Ex. 26 Ex. 27 Ex. 28 Ex. 29Ex. 30 Raw Monomer AM 6 8 7 6 material IBMA 8 6 7 6 8 8 LA 4 6 6 7 6 5 56 4 4 StMA SR351 0.75 0.75 GMA 2 2.25 2.25 2 2 3 3 3 2 2 DCP 3 5 A-DOD-N6 5 6 6 6 3000MK 5 MMA Silica CRS1085- 75 75 60 60 60 60 60 70 65 SF630CRS1015- MSR35TS CRS1035- LER4 TS12- 65 046HA White PC-3 10 10 10 10 1010 10 10 10 10 Talc TP-A25 5 10 10 10 10 10 5 Additive Tinuvin765 0.50.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 StMg 1.5 1.5 1.5 1.5 StZn 1 1.5 1.51 2 1.5 R711 0.5 1 2 1 4 3 Perbutyl E 0.23 0.18 0.25 0.23 Perhexa HC 10.8 1 0.8 1 1 CEL-W-7005 Total [mass %] 100 100 100 100 100 100 100 100100 100 Produc- Molding method LIM LIM LIM LIM LIM LIM LIM LIM LIM LIMtion Whether the flow channel Oc- Not Not Not Not Not Not Not Not Notmethod is shut off or not curred oc- oc- oc- oc- oc- oc- oc- oc- oc-curred curred curred curred curred curred curred curred curred Whetherthe flow channel Not Oc- Oc- Oc- Oc- Oc- Oc- Oc- Oc- Oc- is blocked ornot oc- curred curred curred curred curred curred curred curred curredcurred Results of Occurrence of short ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ evaluationFormation of burrs ◯ Δ Δ ◯ ◯ ◯ ◯ ◯ Δ ◯ Storagiblity at normal ◯ Δ Δ Δ Δ◯ ◯ ◯ ◯ ◯ temperature Shear  10(1/s) 25 13 13 12 12 15 18 20 8 12viscosity 100(1/s) 6 2 2 3 3 4 4 6 1 2 [Pa · s] Light reflectance [%] 9494 94 94 94 94 94 94 94 94 Bending elastic modulus [MPa] 6500 7500 75006500 6500 6500 6500 5500 6000 6500 Bending strength [MPa] 50 50 50 45 4545 45 40 70 50 Heat resistance ◯ ◯ ◯ Δ Δ ◯ ◯ Δ ◯ ◯ Light resistance ◯ ◯◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

TABLE 4 Comp. Comp. Comp. Comp. Comp. Comp. Comp. Comp. Ex. 1 Ex. 2 Ex.3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Raw Monomer AM 2 2 2 material IBMA 24 2424 LA 12 1 12 1 5 12 1 StMA SR351 GMA 6 1 6 1 6 1 DCP A-DOD-N 18 2 18 25 18 2 3000MK MMA 10 Silica CRS1085-SF630 30 69 30 69 70 30 69CRS1015-MSR35TS CRS1035-LER4 TS12-046HA White PC-3 10 25 10 25 10 10 25Talc TP-A25 Additive Tinuvin765 0.5 0.5 0.5 0.5 0.5 0.5 0.5 StMg 1.5 1.51.5 StZn 1.5 1.5 1.5 1.5 R711 Perbutyl E 1 1 1 Perhexa HC 1 1 1 1CEL-W-7005 100 Total [mass %] 100 100 100 100 100 100 100 ProductionMolding method LTM LTM LIM LIM LIM LIM LIM LIM method Whether the flowchannel Occurred Occurred Occurred Occurred Occurred Occurred OccurredOccurred is shut off or not Whether the flow channel Not Not Not Not NotNot Not Not is blocked or not occurred occurred occurred occurredoccurred occurred occurred occurred Results of Occurrence of short ◯ X ◯X — ◯ ◯ X evaluation Formation of burrs X Δ X Δ — X X Δ Storagiblity atnormal X Δ X Δ — X X ◯ temperature Shear  10(1/s) 2 750 2 750 >1000 8 2750 viscosity 100(1/s) 0.1 40 0.1 40 >1000 1 0.1 40 [Pa · s] Lightreflectance [%] 94 95 94 95 — 94 94 94 Bending elastic modulus [MPa]2000 13000 2000 13000 — 5500 2000 13000 Bending strength [MPa] 30 30 3030 — 40 30 30 Heat resistance ◯ ◯ ◯ ◯ — X ◯ ◯ Light resistance ◯ ◯ ◯ ◯ —X ◯ ◯

INDUSTRIAL APPLICABILITY

The composition and the cured product of the invention can be preferablyused as the raw material for a reflector of an optical semiconductorlight-emitting device.

Although only some exemplary embodiments and/or examples of thisinvention have been described in detail above, those skilled in the artwill readily appreciate that many modifications are possible in theexemplary embodiments and/or examples without materially departing fromthe novel teachings and advantages of this invention. Accordingly, allsuch modifications are intended to be included within the scope of thisinvention.

The Japanese application specification claiming priority under the ParisConvention are incorporated herein by reference in its entirety.

The invention claimed is:
 1. A method for producing a thermoset resin,the method comprising: supplying, to a plunger, a thermosettingcomposition comprising: (A) a (meth)acrylate compound having a viscosityat 25° C. of 1 to 300 mPa s with which a substituted or unsubstitutedalicyclic hydrocarbon group including 6 or more carbon atoms isester-bonded, (B) spherical silica, and (C) a white pigment, wherein thethermosetting composition has a shear viscosity at 25° C. and 10s⁻¹ of 1Pa·s or more and 500 Pa·s or less and a shear viscosity at 25° C. and100s⁻¹ of 0.3 Pa·s or more and 100 Pa·s or less; filling, with theplunger, the thermosetting composition into a cavity of a mold; heatcuring the thermosetting composition in the cavity; and removing curedthermoset resin from the mold.
 2. The method for producing a thermosetresin according to claim 1, wherein a temperature of the mold in thecavity is 100° C. or higher and 180° C. or lower.
 3. The method forproducing a thermoset resin according to claim 1, wherein, during thefilling, the thermosetting composition is filled into the cavity of themold through a flow channel of which a temperature is controlled to be50° C. or lower.
 4. The method for producing a thermoset resin accordingto claim 1, wherein a gate system is provided in a flow channel betweenthe plunger and the cavity for shutting off a flow of the thermosettingcomposition and a transfer of heat.
 5. The method for producing athermoset resin according to claim 4, wherein: when a gate of the gatesystem is opened, the thermosetting composition is filled into thecavity of the mold; and during the heat curing, an injection pressure ofthe thermosetting composition is increased after a start of the heatcuring, pressure holding starts before a completion of the heat curing,and after completion of the pressure holding, the gate of the gatesystem is closed to complete the heat curing.
 6. The method forproducing a thermoset resin according to claim 1, wherein the fillingand the heat curing are conducted within 0.2 to 3 minutes.
 7. The methodfor producing a thermoset resin according to claim 1, wherein, in thetheimosetting resin composition: a content of component (B) is 10 to 90mass %; and a content of component (C) is 3 to 50 mass % relative to 100mass % of a total of the components (A) to (C).
 8. The method forproducing a thermoset resin according to claim 1, wherein, in the(meth)acrylate compound (A) of the thermosetting resin composition, thesubstituted or unsubstituted alicyclic hydrocarbon group including 6 ormore carbon atoms is one or more selected from the group consisting of asubstituted or unsubstituted adamantyl group, a substituted orunsubstituted norbornyl group, a substituted or unsubstituted isobornylgroup and a substituted or unsubstituted dicyclopentanyl group.
 9. Themethod for producing a thermoset resin according to claim 1, wherein thethermosetting composition further comprises at least one selected fromthe group consisting of: (D) (meth)acrylic acid or a monofunctional(meth)acrylate compound having a polar group; (E) a monofunctional(meth)acrylate compound other than the components (A) and (D); and (F)at least one polyfunctional (meth)acrylate compound other than thecomponent (A) wherein: a content of the component (C) is 3 to 50 mass %;and a content of the component (B) is 10 to 90 mass %, relative to 100mass % of a total of the components (A) to (F).
 10. The method forproducing a thermoset resin according to claim 1, wherein the sphericalsilica in the thermosetting composition is subjected to a(meth)acrylsilane surface treatment.
 11. The method for producing athermoset resin according to claim 1, wherein an average particle sizeof primary particles of the spherical silica in the thermosettingcomposition is 0.1 to 100 μm.
 12. The method for producing a thermosetresin according to claim 1, wherein the thermosetting compositionfurther comprises at least one of: (G) a plate-shaped filler; and (H)nano particles.
 13. The method for producing a thermoset resin accordingto claim 1, wherein the thermosetting composition consists of: (A) themeth(acrylate) compound having a viscosity at 25° C. of 1 to 300 mPa·swith which a substituted or unsubstituted alicyclic hydrocarbon groupincluding 6 or more carbon atoms is ester-bonded; (B) spherical silica;(C) the white pigment, wherein the white pigment is selected from thegroup consisting of titanium dioxide and barium sulfate; (D) a(meth)acrylic acid or a monofunctional (meth)acrylate compound having apolar group; (G) talc; at least one selected from the group consistingof kaolin, sericite, glass flakes, synthetic hydrotalcite, metal foils,graphite, molybdenum disulfide, tungsten disulfide, and boron nitride;and (H) nano particles, wherein the thermosetting composition has ashear viscosity at 25° C. and 10s⁻¹ of 1 Pa·s or more and 500 Pa·s orless and a shear viscosity at 25° C. and 100s⁻¹ of 0.3 Pa·s or more and100 Pa·s or less.
 14. The method for producing a thermoset resinaccording to claim 13, wherein, in the thermosetting composition, acontent of component (B) is 10 to 90 mass %; and a content of component(C) is 3 to 50 mass %, relative to 100 mass % of a total of thecomponents (A) to (C).
 15. The method for producing a thermoset resinaccording to claim 13, wherein, in the (meth)acrylate compound (A) ofthe thermosetting resin composition, the substituted or unsubstitutedalicyclic hydrocarbon group including 6 or more carbon atoms is one ormore selected from the group consisting of a substituted orunsubstituted adamantyl group, a substituted or unsubstituted norbornylgroup, a substituted or unsubstituted isobornyl group, and a substitutedor unsubstituted dicyclopentanyl group.
 16. The method for producing athermoset resin according to claim 13, wherein, in the thermosettingcomposition: a content of the component (C) is 3 to 50 mass %; and acontent of the component (B) is 10 to 90 mass %, relative to 100 mass %of a total of the components (A) to (D).
 17. The method for producing athermoset resin according to claim 13, wherein the titanium dioxide ispresent.
 18. The method for producing a thermoset resin according toclaim 13, wherein the barium sulfate is present.
 19. The method forproducing a thermoset resin according to claim 1, wherein the whitepigment (C) is titanium dioxide.
 20. The method for producing athermoset resin according to claim 1, wherein the white pigment (C) isbarium sulfate.
 21. The method for producing a thermoset resin accordingto claim 12, wherein the plate-shaped filler is at least one selectedfrom the group consisting of talc, kaolin, mica, clay, sericite, glassflakes, synthetic hydrotalcite, metal foil, graphite, molybdenumdisulfide, boron nitride, plate-shaped iron oxide, plate-shaped calciumcarbonate, and plate-shaped aluminum hydroxide.